How animals live

The giant panda, a member of the bear family, is a carnivore, but has adapted its diet almost exclusively to bamboo, an abundant...Read More >>The giant panda, a member of the bear family, is a carnivore, but has adapted its diet almost exclusively to bamboo, an abundant species of tree in its mountain habitat. It must eat large quantities of bamboo, which is poor in nutrients compared to meat, to give it the energy it needs. The process of evolution ensures that only living things that are suited, or adapted, to their environment will survive. An animal or plant that is poorly adapted to its surroundings soon loses out in the struggle for survival. Animals are adapted to three major features of their environment: the climate (including temperature and rainfall), the food sources available and the predators. The key features of an animal are that it has a body made of many microscopic cells and it gets its energy and nutrients by eating—that is, it takes in or consumes food. Animals can also move about for at least a part of their lives.

Orange tree sponge. Sponges are simple marine animals made up of many cells. Their bodies are full of pores and channels,...Read More >>Orange tree sponge. Sponges are simple marine animals made up of many cells. Their bodies are full of pores and channels, allowing water to circulate through them, from which they extract their food. Although they are sessile (stationary) as adults, sponges swim or drift about freely as larvae (juveniles). A new group of wingless, carnivorous insects was discovered as recently as 2001. Knowns as gladiators or "mantos", they resemble...Read More >>A new group of wingless, carnivorous insects was discovered as recently as 2001. Knowns as gladiators or "mantos", they resemble a cross between mantises and stick insects.

Number of species

Scientists have identified at least 2 million different kinds or species of animal, from tiny worms smaller than a comma, to huge elephants and blue whales. There are almost certainly at least the same number of species still to be identified—for example, insects and other small invertebrates in tropical forests yet to be discovered. The total number of animal species may be far higher: 10 million, or even more.

To protect their almost hairless bodies from the hot African sun (when not submerged in water), hippos have a substance in their skins that forms a sunscreen. It also prevents the growth of disease-causing bacteria.